10 mL of 0.0100 M HCl are added to 25.0 mL of a buffer solution that is 0.010 M HC2H3O2 and 0.1 M C2H3O2-. What is the pH of the resulting solution?
millimols HAc = mL x M = 25 x 0.01 = 0.25
mmols Ac^- = mL x M = 25 x 0.1 = 2.5
mmols HCl = 10 x 0.01 = 0.1
----------------------
......Ac^- + H^+ ==> HAc
I....2.5.....0........0.25
add.........0.1...............
C...-0.1...-0.1......+0.1
E.....?......?.........?
Complete the E line.
Substitue the completed E line into the HH equation and solve for pH.